Spilman, previously head of marketing for the Americas at Yahoo, was appointed chief marketing officer by the company’s former interim chief executive Ross Levinsohn in May, as part of an internal reshuffle at the business.
Yahoo has not announced what new role Spilman will take up, but a spokesman confirmed she will remain at the company.
Savitt joins next month from social commerce company Lockerz, which she founded three and a half years ago.
Her appointment has been overseen by new chief executive Marissa Mayer. Savitt will report directly into Mayer, and will be in charge of all worldwide marketing and branding.
She has experience in consumer marketing, both in retail and technology, having previously held the role of executive vice president and chief marketing officer for US clothing retailer American Eagle Outfitters.
Prior to that she was vice-president of strategic communications, content and initiatives at Amazon.
At the start of this year, Yahoo shook up its European marketing function, parting ways with James Tipple, vice-president for marketing at Yahoo EMEA, and Andrew Cocker, marketing director for EMEA.
Yahoo has been ramping up its consumer marketing in the UK, and in July returned to TV after a three-year hiatus with a campaign to promote its coverage of sport.Follow @shearmans